LTE/EPC (Long term Evolution/Evolved Packet Core) has been standardized with 3GPP as a mobile communication system according to the next generation of the third generation cellular phone network (3G mobile system). LTE/EPC includes an LTE network (wireless access network conforming to LTE: referred to as eUTRAN), and an EPC network (also referred to as SAE (System Architecture Evolution) serving as a core network (mobile transmission network)). The EPC network is connected to an IP (Internet Protocol) network (packet network) via an IMS (IP Multimedia Subsystem) network. Examples of the IP network includes an ISP (Internet Service Provider) network (the Internet) and an intranet.
A mobile station (User Equipment: UE) may be connected to the EPC network via the LTE network, and is connected to the IP network via the EPC network and IMS network. The UE may receive various packet communication services (e.g., Web service, VoIP (Voice over IP)) by accessing various servers and terminal devices connected to the IP network.
The EPC network includes multiple nodes such as MME (Mobility Management Entity), S-GW (Serving Gateway), P-GW (Packet Data Network Gateway), and PCRF (Policy and Charging rule Function). The UE is connected to the IMS network via an S-GW and a P-GW, whereby the UE can access the IP network.
Incidentally, there has been traffic offload technology with traffic reduction in the EPC network as one target. With the traffic offload technology, there is provided an offload device on the EPC network so that traffic from User Equipment accesses the ISP network without passing through an S-GW and a P-GW. The offload device may serve as an anchor point (point to execute handover, i.e., switching of a path) as to traffic from User equipment (wireless access network). The offload device transfers (offloads) the traffic from User Equipment to a network for offload (offload network: e.g., IP network, MPLS (Multi Protocol Label Switching) network) different from the EPC network. The offloaded traffic arrives at (is connected to) the target IP network through the offload network.
Japanese National Publication of International Patent Application Nos. 2004-523148 and 2010-541312 are examples of the related art of the present technology.